Nutational motors are commonly used in applications, such as the operation of large fluid control valves, where the motors must provide high torque at low operating speeds. Nutational motors, such as those set forth in U.S. Pat. Nos. 5,237,234 and 5,672,923, typically include a rotor, a stator having a multiple magnetic lands encircling the rotor, a position sensor sensing the location of the rotor and an electrical sequencer for sequentially producing electromagnetic forces in the lands of the stator to sequentially attract and repel the rotor such that the rotor rotates against the magnetic lands about an axis.
Despite their electrical efficiency, such conventional nutational or electrostatic motors have been used in only a limited number of applications. This is largely due to the fact that the position sensor and the electrical sequencer are both relatively expensive electrical components which occupy space and which add cost to the manufactured motor. The multiple magnetic lands also increase the cost of such motors. As a result, the application of such electrostatic or nutational motors to small consumer products and one-time use products has been impractical.
Thus, there is a continuing need for a nutational or electrostatic motor which has fewer parts, which is compact and which can be easily manufactured at a lower cost.